A Scientist's Mission To Break The Itch-Scratch Cycle

DAVE DAVIES, BYLINE: If you think itch is no big deal, it's probably because you've never had severe chronic itch. You might think, just scratch it and stop complaining. But our guest, Dr. Gil Yosipovitch, understands that itch can be as debilitating as pain. He's the chair of the Department of Dermatology at Temple University and is developing a center for itch there. He's also the founder of the International Forum for the Study of Itch. For years, he's been trying to get doctors in related fields such as neurology and oncology involved in researching new treatments for itch to change what he feels is a dismissive attitude among doctors that itch is the little brother of pain. Dr. Yosipovitch is also the co-author of the book, "Living With Itch: A Patient's Guide." He spoke recently with Terry Gross.

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TERRY GROSS, HOST:

Dr. Yosipovitch, welcome to FRESH AIR. You've been trying to create itch as a separate area of specialization. Why do you want itch to stand on its own as a field?

GIL YOSIPOVITCH: I would say that I learned from my colleagues dealing with pain. A lot of the patients come with that complaint and we can't solve the underlying disease immediately, but they want us to treat their itch first and foremost. And I felt that, like our colleagues in pain that developed the concept that we first have to treat pain regardless of underlying disease, this has to be achieved also in itch. And in fact, we know that patients who have chronic itch, their quality of life is significantly affected by - very similar to patients who have chronic pain.

GROSS: I think a lot of people don't understand that because pain - I mean, pain is pain. And itch is supposed to be, oh, a little thing that you scratch, not a big deal. It doesn't hurt. So give us a sense of what kind of distress itch can cause.

YOSIPOVITCH: When a patient can't sleep at nighttime and wakes up scratching himself all night long, it affects, significantly, his capability of coping and working and enjoying life. So it starts from infancy, where you have kids who have atopic eczema. They can't sleep. Their parents can't sleep. And it also causes a vicious cycle that - often itch, scratch cycle. Patients some (inaudible) I would prefer even having pain rather than having itch. And think about someone who has it constantly, day and night.

GROSS: So, you know, there's the kind of basic itch you get - a mosquito bite, you get a rash, poison ivy. It itches for a while. It goes away. You can treat it and numb it when it's at its worst. But, you know, it's going to go away. But chronic itch doesn't go away. And it's very disturbing to the people who have it - interferes with sleep, interferes with other things as well. It's kind of itch gone berserk. So is the problem neurological? Like, is there something happening with the nervous system when you have that kind of chronic itch?

YOSIPOVITCH: That's an excellent question. And indeed, the neural system is significantly involved. It transmits the itch signals from the skin, where itch emanates, up into the spinal cord and up to the brain. The nerves are acting wacky. They fire when these patients have chronic itch, and we become very sensitive. So even small activities or very minimal activities that usually would not cause us itch like changing our clothes or changes in temperature and environment or exposure to soaps, could irritate this system and the patient feels more itch.

GROSS: So if we look at chronic pain and chronic itch, how are they similar? How are they different?

YOSIPOVITCH: Well, both of them are unpleasant sensations. There's some unique difference and one of the unique differences is that, in pain we retract from the area where we have a painful stimuli. While itch, we actually scratch it. We induce bit of pain to relieve it.

GROSS: Is that what we're doing when we're scratching - inducing pain to relieve the itch?

YOSIPOVITCH: It's interesting. I think there are two aspects to it. Yes, there is a bit component of pain but there is also - and that's unique, I think, to itch - is that there is a component of pleasure and scratching an itch. We find it relieving, but there is something in addition. Our studies and other groups' may suggest that there is a - also a brain mechanism involved in pleasure of scratching an itch and they are involving in this repetitive behavior, so it's bit addictive to start scratching.

And when a doctor tells a patient, stop scratching, it's easy to say that, but in fact, it's not easy to do because it really liberates - the scratching - some chemicals. Chemicals like opioids, like morphine-like. In fact, a lot of the patients say the only way to relieve her itch for a couple of hours is significant scratching.

GROSS: But, I thought if you keep scratching an itch - because of the itch-scratch syndrome, is that what it's called?

YOSIPOVITCH: Cycle.

GROSS: Cycle, yeah. That you are going to make it worse if you have a bad inch. It's defeating to scratch it because you're not only going to scratch your skin and maybe even start bleeding, but also you're going to intensify the itch in the long run and you're just fooling yourself (laughter) if you think that scratching's going to help.

YOSIPOVITCH: You're perfectly correct but, on the other hand, the immediate relief of scratching is something that - that's the purpose most probably, of scratching, is that relief of itch. I think evolutionally this most probably was related to something, that animals were using scratching to relieve insects that were bothering them. My ideal treatment would be to induce an activity that would be similar to scratching but not damaging the skin. When we scratch, we damage the skin to cause inflammation and to activate more of these nerve fibers. But the idea is, if we were able to induce the same activation in the brain of scratching and inducing it without damaging the skin, we may end up with a good treatment for chronic itch.

GROSS: So let me see if I understand correctly - you're not only studying what happens in the brain when we have an itch, you're studying what happens in the brain when we scratch an itch and why that seems to produce a pleasure response. And you're trying to see if there's some kind of substitute we can use other than scratching, some kind of neurochemical thing, that we can do so it would relieve the itch by satisfying the brain?

YOSIPOVITCH: That's correct.

GROSS: That's so interesting. So are you thinking, like someday there's going to be a pill we can take that will basically do for the brain what scratching does?

YOSIPOVITCH: Yes. I do...

GROSS: (Laughter) That would be nice.

YOSIPOVITCH: ...Strongly believe in that. Always, with pills, you have to ask, so what are the side effects? So that's always something that we have to look into. But always, you have to outweigh the risk versus the benefits. And the benefit for a patient who cannot sleep at nighttime sometimes outweighs side effects. But we are on the verge of finding more drugs that are targeted approach for itch. And some of them work clearly on these mechanisms.

GROSS: So we were talking earlier about some of the connections between pain and itch, in terms of the neurological system. So what are some of the implications for medicines? Like, in pain now there's a lot of work being done with things like Gabapentin, to try to slow down the nerve response so that the nerves aren't communicating all this pain. I'm putting this in really bad layperson's terms so you can elaborate on that and explain, but are medications like Gabapentin, which are used to kind of quiet the pain response, also being used to quiet the itch response?

YOSIPOVITCH: I perfectly use them - agree with you - and perfectly use them as my treatments for patients with chronic itch. They don't work for all types, but those where there is neuropathic or damage to the nerve fibers, they work very well. Gabapentin or the Pregabalin; these are drugs that work for our patients. We sometimes use them in combination with other class of drugs from the anti-depression of those called Selective Norepinephrine Reuptake Inhibitor and it's not that our patients are depressed; they could be sometimes depressed due to horrible chronic itch, but because these drugs work in an additive effect, in reducing that sensitization what the nerve fibers as I mentioned, are acting wacky and firing. They reduce that firing of the nerve fibers, that's why it enables our patient to sleep better and to have less itch.

So a lot of times I'm asked by other colleagues, why do you give antidepressant? Why do you give anticonvulsants like Gabapentin, Pregabalin, and I say, I give them because it really reduces the itch intensity and the suffering. So there is a lot of similarities here with chronic pain.

GROSS: Since chronic pain and chronic itch are similar but different, are people who are prone to chronic pain also prone to chronic itch and vice versa?

YOSIPOVITCH: There's not really an epidemiology study to suggest that, but I would say, from my experience, there are a lot of overlaps of people who have some types of chronic pain and they're in the same spectrum of chronic itch, and they could have chronic itch. This is not well mentioned, but for patients who have, for example, fibromyalgia, if it causes chronic pain, a lot of times they complain also of chronic itch. So it won't surprise me, people who have irritable bowel syndrome, which is another form of - all these aspects of disease have something in common - they have a hypersensitization of the nerve fibers and it's very similar to what I described before, with a patient with chronic itch is that the nerves are acting wacky; they're just firing all over. And that's why it's so severe and why it's so difficult to treat these patients.

GROSS: You know, some people who have chronic pain syndromes say that their doctors are very dismissive. And you mentioned fibromyalgia; a lot of doctors don't even consider that a serious diagnosis. Does the same happen with chronic itch? Do you find that a lot of patients who come to you have been dismissed as having either imagined complaints, or neurotic complaints or exaggerated complaints?

YOSIPOVITCH: I agree with you and I think, we in our profession as dermatologists like to see a lot of times, skin signs, rashes. And when a patient tells you that he has itch, that he cannot sleep and - I use, a lot of times, a intensity scale, what we call a visual analog scale and ask him, rate your itch. And I think, for us as dermatologists, it's sometimes very difficult to, if we don't see the scratch marks but the patient tells you, I suffer from horrible itch, it sometimes causes us to think that maybe he's exaggerating. But from my experiences, it's not what you see, it's what the patient complains of. I therefore believe strongly that we need to address itch as a disease - chronic itch as a disease - on its own state and understand our patients' suffering.

GROSS: Now, you're a dermatologist, but a lot of itches you deal with aren't really about the skin - it's not a skin condition, it's not hives, it's not a bite, it's not a rash - it's something that's happening neurologically and you're trying to figure out, what is it that's happening neurologically?

But again, it's not a skin issue, per se.

YOSIPOVITCH: Well, I see it in the perspective of the skin. The skin is a sensory organ and has all the nerves. And the patients come because they think that the dermatologists have to solve it. And it's interesting - I don't want to be critical of my colleagues in neurology but - very few of neurologists are interested in some of those sensations. I would say that, I think one of the purposes of putting itch as a focus of my work is to raise awareness among other specialties, that they have to address this topic, including my colleagues in neurology, including other experts, even pain experts; that they have to understand that sometimes patients have both pain and itch, like, post Shingles.

And they sometimes would dismiss the patient - say, oh, well if you have itch, I'm not bothered with it; we just want to deal with pain.

But, I see that as part of the same spectrum.

GROSS: Dr. Yosipovitch, thank you so much for talking with us. I appreciate it.

YOSIPOVITCH: My pleasure.

DAVIES: Dr. Gil Yosipovitch chairs the Department of Dermatology at Temple University and is the co-author of "Living With Itch: A Patient's Guide." Transcript provided by NPR, Copyright NPR.